1-First Step: Prepare the Aromatics and Meat Mixture Begin by heating half of the olive oil in a large, high-walled skillet over medium heat. Toss in the finely diced yellow onion and minced garlic. Let them soften for about 5 minutes until they are fragrant and translucent. Remove the skillet from the heat and allow the onion and garlic to cool down completely. While those cool, grab a large mixing bowl. Combine the panko breadcrumbs, Parmesan cheese, whisked egg, and milk. Stir them together and let the breadcrumbs soak up the milk for a minute. Add the cooled onion and garlic mixture to the bowl along with the salt, dried oregano, ground allspice, ground nutmeg, and pepper. Mix everything thoroughly.

2-Second Step: Mix and Shape the Meatballs Now it is time to add the meats. Add the ground beef and ground pork to the bowl with the seasoning mixture. Gently mix everything together with your hands or a spoon. Be careful not to overwork the meat, as this can make the meatballs tough. You just want the ingredients combined. Once mixed, scoop out portions of the meat and roll them into balls that are about 1½ inches in diameter. Place them on a plate or a cookie sheet as you go. Pop the tray into the fridge to chill for at least 15 minutes, or you can leave them overnight covered. Chilling helps them hold their shape during cooking.

3-Third Step: Brown the Meatballs Take the meatballs out of the fridge. Heat the remaining olive oil in your skillet over medium-high heat. Add the meatballs in batches, being careful not to crowd the pan. Brown them on all sides, which should take about 1 minute per side. You are not looking to cook them all the way through yet, just get a nice golden crust on the outside. Once browned, remove the meatballs from the skillet and set them aside on a clean plate. Drain any excess oil left in the pan, leaving behind the tasty browned bits for the sauce.

4-Fourth Step: Create the Creamy Sauce While the meatballs are resting, mix up your sauce liquids. In a spouted measuring cup, combine the beef broth, chicken bouillon cube, Worcestershire sauce, Dijon mustard, and dried parsley. Stir until the bouillon is mostly dissolved and set this aside. In the same skillet you used for the meatballs, melt the butter over medium heat. Sprinkle the flour into the butter and stir constantly. Cook this roux for about 2 minutes until it turns a light brown color and smells nutty. Slowly pour in the broth mixture while whisking continuously to prevent lumps. Bring the liquid to a boil, then reduce the heat to a simmer.

5-Final Step: Combine and Simmer To finish the sauce, place the sour cream in a separate bowl. Take a small amount, about ¼ cup, of the warm sauce from the skillet and slowly whisk it into the sour cream. This tempers the cream so it does not curdle when added to the hot pan. Once smooth, pour the sour cream mixture back into the skillet and stir on low heat until everything is well combined. Add the browned meatballs back into the skillet along with any juices that collected on the plate. Spoon the sauce over the top of the meatballs. Cover the skillet partially and let it simmer for 10 to 15 minutes. This finishes cooking the meatballs and lets the flavors meld together. Garnish with fresh parsley before serving over noodles or mashed potatoes.